It it tradition that lay people should not study the vinaya in depth.
That being said, it is only in very particular circumstance that one monastic can ordain another. It requires a group of monastics for an ordination to be valid.

There is a nun called Ayya Yeshe. Who is very active and such a public person.
So the question arise. What is she doing?
Quickly seen I did not find any mention her qualification to ordain women?

If some one have more insight I would be happy to hear.

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Any vow holding monastic is "qualified" to ordain given there are another two (for a total of three) vow holding monastics present.

Why do you want to know? You want to be ordained by her?

"My religion is not deceiving myself."Jetsun Milarepa 1052-1135 CE

"Butchers, prostitutes, those guilty of the five most heinous crimes, outcasts, the underprivileged: all are utterly the substance of existence and nothing other than total bliss."The Supreme Source - The Kunjed Gyalpo
The Fundamental Tantra of Dzogchen Semde

"Butchers, prostitutes, those guilty of the five most heinous crimes, outcasts, the underprivileged: all are utterly the substance of existence and nothing other than total bliss."The Supreme Source - The Kunjed Gyalpo
The Fundamental Tantra of Dzogchen Semde

There is a nun called Ayya Yeshe. Who is very active and such a public person.
So the question arise. What is she doing?

She engaged in teaching Dharma in HIV hospices, schools, drug and alchohol rehab centres; she also trained as a yoga teacher.

When she came to India in 2004, Venerable Yeshe studied for two years in a monastery, but felt a need to make Buddhism accessible and socially engaged while still trying to maintain her contemplative way of life. She met Indian Buddhists in 2005 and has been working with them ever since. Her teachers are Sakya Trizen, the second highest Lama in Tibetan Buddhism; and Venerable Thich Nhat Hanh, the nobel peace prize poet and peace activist. Ayya Yeshe Bodhicitta is the author of ‘Everyday Enlightenment’ published by Harper Collins and is featured in the documentaries ‘life beyong the begging bowl’ and ‘Through the Eastern Gate’.

She is engaged in Social Dharma work.

Quickly seen I did not find any mention her qualification to ordain women?

Where is it mentioned that she is ordaining people? Having said that, Gegoris's statement on ordination is correct but I'm not sure that that is actaully followed in practice even in the Mahayana.

"Even if you practice only for an hour a day with faith and inspiration, good qualities will steadily increase. Regular practice makes it easy to transform your mind. From seeing only relative truth, you will eventually reach a profound certainty in the meaning of absolute truth."
Kyabje Dilgo Khyentse Rinpoche.

The different sūtras in accord with the emptiness
taught by the Sugata are definitive in meaning;
One can understand that all of those Dharmas in
which a sentient being, individual, or person are taught are provisional in meaning.

Well, not exactly. Bhikṣunis cannot ordain men. They can at most give them refuge (barring bodhisattva vows and samaya, which do not have gender restrictions).

Yeah, I know. The statement is in the context of a discussion about a nun ordaining women.

"My religion is not deceiving myself."Jetsun Milarepa 1052-1135 CE

"Butchers, prostitutes, those guilty of the five most heinous crimes, outcasts, the underprivileged: all are utterly the substance of existence and nothing other than total bliss."The Supreme Source - The Kunjed Gyalpo
The Fundamental Tantra of Dzogchen Semde

"Butchers, prostitutes, those guilty of the five most heinous crimes, outcasts, the underprivileged: all are utterly the substance of existence and nothing other than total bliss."The Supreme Source - The Kunjed Gyalpo
The Fundamental Tantra of Dzogchen Semde